Drill bit



Sept. 27, 1955 w. B. NOBLE DRILL BIT Filed Aug. l, 1952 .1 bink kiwi] United States Patent O DRILL BIT Wiley B. Noble, Houston, Tex., assignor to Reed Roller Blt Company, Houston, Tex., a corporation of Texas Application August 1, 1952, Serial No. 302,198

6 Claims. (Cl. Z55-313) This invention relates generally to drill bits and more particularly to a new construction for a roller drill bit.

A general object of this invention is to provide a new and improved drill bit structure which may be fabricated with facility and economy.

Drill bits in common use may employ drilling iiuid nozzles adapted to direct fluid being pumped therethrough toward the bottom of the hole being drilled to clean therefrom cuttings dislodged by the drilling operation. The drilling fluid may be pumped at high velocities through the nozzles, and the iluid may have entrained therein abrasive particlesV such as sand and particles of the formation being drilled. If this abrasive laden fluid passing through the nozzles at high velocities is made to change direction sharply, it may cause turbulence of the fluid and may erode or cut through the nozzle; whereupon, the high velocity fluid may impinge the drill bit rollers and adjacent parts thereby eroding them, thus reducing the useful life of the drill bit, and changing the desired course of the high velocity fluid.

The drill bit also may be damaged by surveying instruments and other objects dropped into or pumped through the drill stern to the drill bit. The instruments or objects thus dropped may break the high velocity iiuid nozzle or dislodge it from its desired position in the drill bit.

lt is an object of this invention to providea new and improved drill bit wherein a high velocity fluid nozzle having gently diverging passageways may be economically mounted therein.

Another object is to provide a new and improved device in a drill bit to protect the bit from damage which may be caused by objects being dropped through the drill stem to the drill bit.

Other objects will hereinafter appear from the following description and drawings wherein, by way of illustration, this invention is set forth.

Referring to the drawings;

Fig. l is an elevation partly in section of a drill bit with a high velocity nozzle disposed therein;

Fig. 2 is a top plan view of the collar from the line 2-2 of Fig. l.

Referring to the drawings, the drill bit is indicated generally by the letter A. It may be composed of a plurality of segmental sections 1 the depth of each section being indicated by the dotted line 20, and adapted to fit together to form an annular head 2; a fluid nozzle 3 is disposed within the bore 4 of the annular bit head 2. The lower portions of the segmental sections 1 extend downwardly and inwardly to form bearing extensions 5 on which may be rotatably mounted, in the usual manner, rollers 6, 7 and 8. The upper ends 9 of the segmental sections 1 are adapted to form a portion of a threaded shank 10 which is adapted to be connected to a conventional drill stem (not shown). An annular collar 11 is secured to the upper ends 9, in substantial alignment therewith, by means of weld 12 or other suitable means. The annular collar 11 is threaded to form a portion of the said threaded shank 10. The collar 11 has inwardly disposed lugs 13 therein, as is clearly shown in Fig. 2, to prevent damage to the slush nozzle 3 or to the drill bit which may be caused by objects dropped through the drill stem to the drill bit. The slush nozzle 3 has downwardly and outwardly diverging iluid passageways 14 adapted to direct drilling fluid toward the bottom of the hole being drilled by the drill bit.

ln operation, drilling fluid is pumped downwardly through the drill stern and drill bit to remove cuttings dislodged bythe drilling operation, and carry them upwardly, in the space between the drill stern and the wall of the hole, to the surface of the earth. As hereinabove stated, if the drilling iiuid is caused to diverge sharply in its course from the longitudinal axis or center-line of the drill bit, it may cause turbulence of the liuid, thereby eroding through the nozzle and causing corresponding wear and damage to the drill bit and iiuid nozzle. I propose to lengthen the drill bit to accommodate satisfactorily the high velocity fluid nozzle 3 which may have gently diverging fluid passageways 14 to reduce the iluid turbulence. It is obvious that the upper portions 9 of the segmental sections 1 could be lengthened to obtain a correspondingly longer drill bit, but since the segmental sections l usually have rollers mounted on the bearing extensions 5 thereof, the said bearing extensions usually are forged of a high grade steel, of suitable quality to provide satisfactory bearing races for the said rollers. I propose to lengthen the bit by addition ofthe annular collar 11 which may be made of any suitable low grade steel and may be a casting. The high grade steel required for the bearing extensions 5 is not required to provide a satisfactory threaded shank 1t) for connection to the drill stem; thus the collar 11 may be utilized to form a portion of the threaded shank 10 and may serve to provide the additional drill bit length desired. Further, if the upper portions 9 of the segmental sections 1 were lengthed to obtain a longer drill bit, the existing multiple spindle machinery used in machining the sections 1 may not accommodate physically the said lengthened sections: thus new machinery may be necessary to machine the longer sections or it may be required to machine the said sections singly at increased cost in time and labor. These longer segmental sections would also require new, larger and expensive forging dies to forge these sections. Thus it can be seen that the addition of the collar 11 serves to provide the additional drill bit length desired without the necessity of employing longer, high grade steel forgings.

ln the annular collar 11, I provide lugs 13 which project inwardly of the collar, and serve to protect the fluid nozzle and the drill bit from damage which may be caused by objects dropped or pumped through the drill stem to the drill bit.

During the drilling operation, surveying instruments may be dropped or pumped to the drill bit, as above stated, for the purpose of determining the deviation of the bore hole from the vertical, or for other purposes. Thus, it is desirable that the surveying instrument be centered with respect to the longitudinal axis, or centerline, of the drill stern and drill bit at the moment the instrument reaches the drill bit. The lugs 13 of the collar 11, as shown in Fig. 2, are adapted to center the surveying instrument at the moment of the impact with the said lugs, and to prevent damage to the bit which may be caused upon further downward travel of the instrument. The lugs 13 are spaced radially inwardly of the collar 11 and are arranged in a predetermined, spaced relationship to permit the passage of drilling fluid thereby; to limit the downward travel of the surveying instrument dropped thereto; and to center the said instrument as it strikes the said lugs 13.

This invention is not limited to the embodiment shown.

Various changes, within the scope of the following claims, will be apparent to those skilled in the art.

I claim:

1. In a drill bit, segmental sections adapted to be joined together to form an annular head, each of said sections having a downwardly and inwardly extending bearing extension and adapted to accommodate a roller to be rotatably mounted on the lower portion thereof, a drilling fluid nozzle disposed within said annular head, an annular collar secured to the upper ends of said sections in substantial register with the outer surface of said sections, the upper ends of said sections and the collar having threads thereon to provide a shank for connection to a drill stem, said annular collar having inwardly extending lugs thereon to prevent damage to the drill bit from objects dropped through the drill stern to the drill bit.

2. In a drill bit, segmental sections adapted to be joined together to form an annular head, each of said sections having a downwardly and inwardly extending bearing extension and adapted to accommodate a roller, a drilling uid nozzle within said annular head, an annular collar secured to the upper ends of said sections in substantial register with the outer surface of said sections, the upper ends of said sections and the collar having threads thereon to provide a shank for connection to a drill stem, said annular collar having inwardly extending lugs thereon to prevent damage to the drill bit from objects dropped through the drill stem to the drill bit.

3. In a drill bit, segmental sections adapted to be joined together to form an annular head, each of said sections having a downwardly and inwardly extending bearing extension and adapted to accommodate a roller, a drilling uid nozzle disposed Within said annular head, an annular collar secured to the upper ends of said sections, the upper ends of said sections and the collar having threads thereon to provide a shank for connection to a drill stem, said annular collar having inwardly extending lugs.

4. In a drill bit, segmental sections adapted to t together to form an annular head, a drilling fluid nozzle disposed within said head, the lower portions of said sections having bearing extensions and rollers rotatably mounted thereon, the upper ends of said sections adapted to form a portion of a threaded shank, an annular collar secured to said upper ends of said sections in substantial alignment therewith, said collar adapted to be threaded to form an extension of said threaded shank, said collar having inwardly disposed lugs therein to protect the drill bit from objects dropped to the drill bit.

5. In a drill bit, segmental sections adapted to it together to form an annular head, a drilling uid nozzle disposed within said head, the lower portions of said sections having bearing extensions and rollers rotatably mounted thereon, the upper ends of said sections adapted to form a portion of a threaded shank, an annular collar secured to said upper ends of said sections, said collar adapted to be threaded to form a portion of the threaded shank, said collar having inwardly disposed lugs therein to protect the drill bit from objects dropped to the drill bit.

6. A bit head comprising segmental sections adapted to lit together to form an annular head, a drilling uid nozzle disposed within said head, the lower portions of said sections having bearing extensions and rollers rotatably mounted thereon, an annular collar having inwardly extending lugs therein, secured to the upper ends of said sections, said collar and said upper` ends of said sections being threaded to form a threaded shank.

References Cited in the ile of this patent UNITED STATES PATENTS 1,945,258 Collins Ian. 30, 1934 2,293,259 Johnson Aug. 18, 1942 2,317,010 Wingard Apr. 20, 1943 2,592,277 Hammer Apr. 8, 1952 

